This invention relates to a biodegradable protective low density packaging material and method for making the same.
High amylose starch packaging materials have been widely known for several years. One example of such a product is disclosed and claimed in U.S. Pat. No. 4,863,655, issued Sept. 5, 1989. The expanded product, disclosed in this patent, requires at least 45% amylose content by weight. This high amylose starch content is costly and also makes the product very susceptible to shrinking and deterioration in hot humid storage conditions. The end product must be resilient and dimensionally stable within the temperatures encountered during shipping and storage. The product must also be liquid soluble, biodegradable, compostable and made from renewable (recyclable) ingredients.